TW201336904A - Method and apparatus for producing cellulose acylate film - Google Patents

Abstract

Fatty acid is dissolved in a second solvent to prepare a fatty acid solution. The fatty acid solution is added to a dope prepared by dissolving cellulose acylate and a plasticizer in a first solvent. Thereby, a casting dope containing the fatty acid is prepared. The mass of the fatty acid to be added to the dope is in the range of 1*10<SP>-4</SP> to 3*10<SP>-3</SP> relative to the sum of the mass of the cellulose acylate and the mass of the plasticizer. The casting dope is discharged from a casting die to the circumferential surface of a drum to form a casting film. The casting film is peeled from the drum and dried to be a film.

Description

Method and device for manufacturing cellulose oxime film

The present invention relates to a method and apparatus for producing a cellulose oxime film.

As is well known, the solution film forming method is a method in which a dope in which a polymer is dissolved in a solvent is cast on a support to form a cast film, and the cast film is peeled off as a wet film and dried. Thereby, a film is produced. A cellulose oxime film which is often used for optical purposes is produced by this solution film forming method.

The cellulose oxime film is used, for example, as a viewing angle widening film or a polarizing plate protective film constituting a liquid crystal display. In recent years, with the rapid expansion of the liquid crystal display market, the demand for cellulose oxime film has also increased rapidly. Therefore, there is a need to substantially increase the amount of manufacturing in existing equipment.

In order to increase the film production by the existing solution film forming apparatus, the belt or the drum as the casting support is rotated at a higher speed. Further, the casting of the dope and the peeling of the casting film are repeatedly performed on the casting support, and the number of times of repetition per unit time increases with the production speed of the acceleration film. There is a variation due to the composition of the dope or the casting conditions, the peeling conditions, and the like, but the casting support is contaminated more quickly as the production speed of the accelerated film is increased. Further, when the production of the film is continued in a state where the casting support is contaminated, there is a problem that the smoothness of the film surface is impaired or the scale of the casting support adheres to the film. Therefore, it is necessary to clean the casting support. However, the cleaning must be stopped by the manufacture of the film, and the longer the time required for the cleaning or the higher the frequency of the cleaning, the lower the productivity of the film.

In the case of the contamination of the casting support, it is confirmed that the substance contained in the casting film is gradually increased to the extent that it cannot be visually recognized and becomes dirty. In the following description, the stain phenomenon thus confirmed is referred to as precipitation. As a method for preventing precipitation, various proposals have been made so far, for example, the method described in Japanese Patent Laid-Open Publication No. 2008-063403, which is based on the quality of the cellulose telluride and the quality of magnesium contained in the cellulose halide. The ratio is set to a predetermined range to prevent precipitation. Further, Japanese Patent Publication No. 2011-006603 discloses that the amount of calcium in the dope is The method in which the amount of magnesium and the amount of sulfuric acid are set to a predetermined range and the compound of the predetermined skeleton is contained in the dope. Thereby, precipitation is suppressed, and yellowing of the film is prevented.

As a method of preventing precipitation, the method described in Japanese Patent Laid-Open Publication No. 2008-063403 and Japanese Patent Publication No. 2011-006603 has a certain effect. However, even if these methods are used, precipitation sometimes occurs, so these methods cannot be said to be a method of completely suppressing precipitation. The contamination which can be confirmed in the precipitation is a so-called paraffin contained in the cellulose halide, and the paraffin is mainly a fatty acid, a fatty acid salt, or a fatty acid ester. Among them, the fatty acid ester easily damages the smoothness of the film surface. Further, since the cooling casting can increase the manufacturing speed as compared with the dry casting, the productivity is excellent. However, compared with dry casting, cooling casting is more likely to cause precipitation than dry casting, and in particular, fatty acid esters are easily precipitated on the casting support. Since the fatty acid ester has a large molecular weight, it is difficult to dissolve with respect to a large amount of liquid as a solvent. Therefore, it is difficult to remove the fatty acid ester even if it is washed, that is, it is difficult to completely remove it by wiping with, for example, a cloth impregnated with a solvent, and it takes a lot of time to remove it. Further, the cooling casting is a method of cooling and solidifying the casting film on the casting support, and the drying casting is a method of drying and solidifying the casting film on the casting support.

Accordingly, an object of the present invention is to provide a method and an apparatus for producing a cellulose oxime film which can be easily removed from a casting support by precipitation using a cellulose hydride containing a fatty acid ester to cause precipitation.

The method for producing a cellulose oxime film of the present invention includes an adding step (A step), a casting step (B step), a peeling step (C step), and a drying step (D step). In the step A, a fatty acid having a carbon number of 12 or more and 22 or less is added to the cellulose halide solution. The cellulose halide solution is a liquid in which a cellulose halide and a plasticizer are dissolved in a solvent. A fatty acid having a ratio of the mass of the fatty acid to the sum of the mass of the cellulose halide and the plasticizer in an amount of from 1 × 10 ^{-4 to} 3 × 10 ^-3 or less is added to the cellulose halide solution. The B step casts the cellulose halide solution to which the fatty acid is added to the surface of the support to form a cast film. The support is circulated at the casting position and the peeling position. The casting position is where the cellulose halide solution is cast. The peeling position is a position at which the casting film formed by casting is peeled off. The C step peels off the cast film from the surface of the support. The D step of drying the peeled cast film.

The fatty acid is preferably a linear fatty acid.

The fatty acid is preferably a saturated fatty acid.

The fatty acid solution is prepared by dissolving the fatty acid in a solvent, and it is preferred to add the fatty acid solution to the cellulose halide solution in the A step.

It is preferred to continuously supply the cellulose halide solution to the casting apparatus subjected to the B step, and continuously add the fatty acid solution to the cellulose halide solution flowing toward the casting apparatus.

The apparatus for producing a cellulose oxime film of the present invention includes an addition portion, a casting device, a casting die, a support, a peeling portion, and a drying device. The addition portion adds a fatty acid having a carbon number of 12 or more and 22 or less to the cellulose halide solution. The cellulose halide solution is a liquid in which a cellulose halide and a plasticizer are dissolved in a solvent. A fatty acid having a ratio of the mass of the fatty acid to the sum of the mass of the cellulose halide and the plasticizer in an amount of from 1 × 10 ^{-4 to} 3 × 10 ^-3 or less is added to the cellulose halide solution. The casting device forms a cast film from a cellulose halide solution to which fatty acid is added. The casting die allows the cellulose halide solution to which the fatty acid is added to flow out. The casting die is placed on the casting device. The support is circulated at the casting position and the peeling position. The support body is disposed on the casting device. The casting position is where the cellulose halide solution is cast. The peeling position is a position at which the casting film formed by casting is peeled off. The peeling portion peels the cast film from the support. The peeling cast film is dried by a drying device.

According to the present invention, even if precipitation is caused by using a cellulose halide containing a fatty acid ester, it is possible to easily remove dirt from the casting support by washing.

10‧‧‧solution film making equipment

11‧‧‧Concentrate manufacturing unit

12‧‧‧ Film manufacturing unit

15‧‧‧1st dissolution device

16‧‧‧Second dissolving device

17‧‧‧Mixed device

18‧‧‧casting mode

19‧‧‧ plasticizer

20‧‧‧ Cellulose Telluride

21‧‧‧1st solvent

22‧‧‧Liquor

25‧‧‧ fatty acids

26‧‧‧2nd solvent

27‧‧‧ fatty acid solution

30‧‧‧Running dope

31‧‧‧Valves

34‧‧‧casting device

35‧‧‧ tenter

36‧‧‧Roll drying device

37‧‧‧Winding device

40‧‧‧ film

41‧‧‧Roller

42‧‧‧cast film

45‧‧‧ peeling roller

46‧‧‧ needle board

47‧‧‧ catheter

50‧‧‧roll

L1‧‧‧1st piping

L2‧‧‧2nd piping

PA‧‧‧Add location

PC‧‧‧ casting position

PP‧‧‧ peeling position

Fig. 1 is a schematic view showing a solution film forming apparatus which performs a solution film forming method.

<solution film making equipment>

The cellulose vaporized film is produced, for example, by the solution film forming apparatus 10 shown in Fig. 1. The solution film forming apparatus 10 includes a dope manufacturing unit 11 and a film manufacturing unit 12.

The dope production unit 11 has a first dissolution device 15, a second dissolution device 16, and a mixing device 17. The first dissolution device 15 is connected to the casting die 18 of the film production unit 12 via the mixing device 17 . The first dissolution apparatus 15 mixes the supplied cellulose halide 20, the plasticizer 19, and the solvent of the cellulose halide 20 (hereinafter referred to as a first solvent) 21, and the mixture is stirred or heated to thereby cellulose. The telluride 20 is dissolved in the first solvent 21. Thereby, a cellulose halide solution (hereinafter referred to as a dope) 22 is obtained. In addition, the first dissolution device 15 can be supplied with fibers. The bismuth telluride 20 and the other materials different in the first solvent 21 are mixed with the cellulose oxime film 20 and the first solvent 21. As other substances, there are, for example, a matting agent, an ultraviolet absorber, and the like.

The second dissolution device 16 mixes the supplied predetermined fatty acid 25 with a solvent of the fatty acid 25 (hereinafter referred to as a second solvent) 26, and the mixture is stirred or heated to dissolve the fatty acid 25 in the second solvent 26. Thereby, the fatty acid solution 27 was obtained. The predetermined fatty acid 25 will be described later.

The second dissolution device 16 is connected to the first pipe L1 that connects the first dissolution device 15 and the mixing device 17. Thereby, the fatty acid solution 27 is added to the dope 22. The fatty acid solution 27 is added to the dope 22 to obtain a casting dope 30 containing the fatty acid 25. Hereinafter, the process of adding the fatty acid 25 in this manner is referred to as an addition process. Further, the first pipes L1 are extended from the mixing device 17 to the casting die 18 to connect them. The valve 31 is provided in the second pipe L2 that connects the second dissolution device 16 and the first pipe L1, and the supply amount of the fatty acid solution 27 to the first pipe L1 is controlled by adjusting the opening degree of the valve 31. The mass of the fatty acid 25 added to the dope 22 is controlled by controlling the supply amount of the fatty acid solution 27. The amount of the fatty acid 25 added to the dope 22 will be described later.

In the present embodiment, the dope 22 obtained in the first dissolution device 15 is continuously supplied to the casting die 18, and the fatty acid solution 27 is continuously added to the dope 22 from the first dissolution device 15 toward the casting die 18. When the viscosity of the dope 22 and the fatty acid solution 27 are greatly different, it may be difficult to uniformly mix the two. At this time, in the present embodiment, the mixing device 17 is disposed between the addition position PA and the casting die 18, and the mixture of the concentrated liquid 22 and the fatty acid solution 27 guided by the mixing device 17 is made uniform. The solution is OK. The addition position PA is a position at which the fatty acid solution 27 is added to the dope 22. As the mixing device 17, for example, a static mixer is preferred. As a static type mixer, a static mixer, a Sulzer mixer, etc. are mentioned.

The addition process may be a mode in which the fatty acid 25 is directly supplied to the dope 22 without being dissolved in the second solvent 26. At this time, the second dissolution device 16 is not used. However, from the viewpoint of the fatty acid 25 being more quickly and reliably mixed in the concentrated liquid 22, the fatty acid 25 is dissolved in the second solvent 26 to produce the fatty acid solution 27, and the fatty acid solution 27 is supplied to the dope. 22 is preferred.

The film manufacturing unit 12 includes a casting device 34, a tenter 35, a roll drying device 36, and a winding device 37 in this order from the upstream side.

In addition, the solvent content rate (unit: %) in this specification is a value based on a dry amount. Specifically, when the mass of the solvent (the sum of the masses of the first solvent 21 and the second solvent 26) is x, and the mass of the film 40 is y, the solvent content (unit: %) is {x/ (yx)}×100 to find the percentage.

The casting device 34 includes a drum 41 as a casting support, and a casting die 18 that allows the supplied casting dope 30 to flow out is provided above the drum 41. The casting process continuously flows the casting dope 30 from the casting die 18 to the drum 41 which is rotated in the circumferential direction. Thereby, the casting dope 30 is cast on the drum 41 to form the casting film 42. In FIG. 1, the position where the casting dope 30 is in contact with the drum 41 and the formation of the casting film 42 (hereinafter referred to as a casting position) is attached with a symbol PC.

The drum 41 is provided with a temperature controller (not shown) that controls the temperature of the circumferential surface. The temperature of the casting film 42 is adjusted by the drum 41 which has controlled the peripheral temperature. For example, when the cooling surface is delayed, if the circumferential surface temperature is in the range of -15 ° C or more and 10 ° C or less, the casting film 42 is cooled and gelled. The cast film 42 is solidified by the gelation to such an extent that it can be transported.

Further, as the casting support, an endless belt (not shown) formed in a ring shape may be used instead of the drum 41. When a belt is used as the casting support, the belt is wound around the circumferential surface of a pair of rolls (not shown) that rotate in the circumferential direction. At least one of the pair of rollers may be a drive roller having a drive mechanism. The belt in contact with the circumferential surface is conveyed by the driving roller rotating in the circumferential direction. With this transfer, the belt circulates and continuously travels in the longitudinal direction. When a belt is used as the casting support, a temperature controller (not shown) for controlling the temperature of the peripheral surface is provided on the pair of rolls, and the belt contacting the circumferential surface of the rolls is controlled by controlling the peripheral surface temperature of each of the rolls. The temperature can be.

Regarding the casting dope 30 from the casting die 18 to the drum 41, a so-called liquid bead is provided with a decompression chamber (not shown) upstream of the rotation direction of the drum 41. The decompression chamber sucks the atmosphere of the upstream side region of the casting dope 30 flowing out from the casting die 18 and depressurizes the zone.

After the casting film 42 is solidified to such an extent that it can be conveyed to the tenter 35, it is peeled off from the circumferential surface of the drum 41 in a state containing a solvent. In the case where the cooling flow is delayed, the peeling process removes the casting film 42 in a range of, for example, a solvent content of 150% by mass or more and 280% by mass or less. At the time of peeling, the film 40 is supported by a peeling roller (hereinafter referred to as a peeling roll) 45, and the peeling position PP at which the cast film 42 is peeled off from the drum 41 is kept constant.

As described above, the film 40 is formed from the casting dope 30 by the casting device 34. The circumferential surface of the rotating drum 41 is circulated at the casting position PC and the peeling position PP, and the casting of the casting dope 30 and the peeling of the casting film 42 are repeatedly performed on the drum 41.

A blowing device (not shown) may be disposed on the conveying path between the casting device 34 and the tenter 35. The film 40 is dried by blowing air from the air blowing device. The peeled cast film 42, that is, the film 40, is guided to the tenter 35.

The tenter 35 includes a plurality of needle plates 46 as a holding member for holding the side portions of the elongated film 40, a pair of guide rails (not shown), and a chain (not shown). The needle plate 46 is a plurality of needles (not shown) that are disposed on the upper surface of the table in an upright posture. The tenter 35 holds the needles of the needle plate 46 through the respective side portions of the film 40 to hold the side portions of the film 40.

The guide rails are provided on the respective side portions of the conveying path of the film 40, and the pair of guide rails are disposed separately. The chain is hung on the drive sprocket and the driven sprocket (not shown), and is movably mounted along the guide rail. A plurality of needle plates 46 are attached to the chain at predetermined intervals. The needle plate 46 is cyclically moved along the guide rail by the rotation of the drive sprocket. The needle plate 46 begins to hold the guided film 40 near the entrance of the tenter 35 and moves toward the outlet, and is released from the vicinity of the outlet. The release needle plate 46 is again moved to the vicinity of the entrance and the film 40 guided back is again held. The film 40 is held by the needle plate 46 at each side portion and conveyed in the longitudinal direction.

In the tenter 35, a duct 47 is provided above the transport path of the film 40. An outlet (not shown) through which the drying gas flows out is formed on the lower surface of the conduit 47, and the film 40 is dried while being conveyed in the tenter 35 by blowing out the dry gas. Further, a duct having the same structure may be disposed below the transport path of the membrane 40.

The roller drying device 36 includes a plurality of rollers 50 and an air conditioner (not shown). A plurality of rollers 50 support the film 40 on the circumferential surface. The film 40 is wound around the roll 50 and the transfer path is determined. The air conditioner adjusts the temperature, humidity, and the like inside the roller drying device 36. Thereby, the film 40 is also dried during transport in the roll drying device 36. Thus, the drying of the film 40 is performed in both the tenter 35 and the roll drying device 36.

When the film 40 is sent to the winding device 37, it is wound into a roll shape. As described above, the film 40 is produced from the casting dope 30 in the film manufacturing unit 12.

A slitter (not shown) may be disposed downstream of the tenter 35, and the holding trace of the film 40 generated by the needle of the needle plate 46 may be cut. Further, in order to exhibit a target optical characteristic, for example, in the film 40, a tenter (not shown) may be further disposed between the tenter 35 and the roll drying device 36 or downstream of the roll drying device 36. The tenter performs a process of stretching the film 40 or the like in the width direction.

The obtained film 40 can be utilized as an optical film. As an optical film, a protective film of a polarizing plate or a retardation film is mentioned, for example.

In the case of forming a multilayer cast film by successive casting or co-casting, the above-mentioned casting dope 30 is used to form a casting dope which is a layer which is in contact with the drum 41 among a plurality of casting dopes used. can.

Detailed description of the added process. In the addition process, the predetermined fatty acid 25 having a mass in the range of 1 × 10 ^-4 or more and 3 × 10 ^-3 or less in terms of the mass of the solid content contained in the dope 22 is added to the dope 22. In other words, when the mass of the solid content in the dope 22 is M1 and the mass of the fatty acid 25 is M2, the fatty acid having M2/M1 in the range of 1 × 10 ^-4 or more and 3 × 10 ^-3 or less is obtained. The amount of 25 is added to the dope 22 in the amount of fatty acid 25 obtained. Thereby, the cleaning property is improved. Good cleanability means that it is easy to remove dirt by washing, and dirt can be removed in a shorter time and more reliably. Further, the solid content contained in the dope 22 is the cellulose halide 20 and the plasticizer 19, and even if other solid components enter the dope 22, the quality of other solid components can be ignored.

By adding the predetermined fatty acid 25 to the dope 22, the added fatty acid 25 is deposited on the circumferential surface of the drum 41 together with the fatty acid ester. The solubility of the fatty acid 25 with respect to the solvent is higher than that of the fatty acid ester, and therefore, it is easily removed by washing. The fatty acid ester is removed together with the fatty acid 25.

However, when the mass ratio of the fatty acid 25 relative to the solid content of the dope 22 is less than 1 × 10 ^-4 , the effect of the cleaning property cannot be said to be reliable. In addition, when the mass ratio of the fatty acid 25 to the solid content of the dope 22 is more than 3 × 10 ^-3 , the cleaning effect is obtained, but whitening occurs in the obtained film 40, which is not preferable.

In the present embodiment, when the fatty acid 25 is added to the dope 22 in a state of being dissolved in the second solvent 26, the fatty acid solution 27 is supplied to the dope 22 so that the mass of the solid content of the dope 22 becomes 1 × 10 ^- The fatty acid 25 is added to the dope 22 in a mass ratio of ⁴ or more and 3 × 10 ^-3 or less. The fatty acid solution 27 is supplied to the dope 22, and there are two methods in which M2/M1 is in a range of 1 × 10 ^-4 or more and 3 × 10 ^-3 or less. One is a method in which the mass of the fatty acid solution 27 supplied to the unit mass of the liquid 22 is made constant, and the concentration of the fatty acid 25 in the fatty acid solution 27 is adjusted. The other method is a method in which the concentration of the fatty acid 25 in the fatty acid solution 27 is made constant, and the mass of the fatty acid solution 27 supplied to the unit mass of the liquid 22 is adjusted.

From the viewpoint of the solubility of the fatty acid 25 with respect to the dope 22, the concentration of the fatty acid 25 in the fatty acid solution 27 is made constant in the range of 1% or more and 5% or less, and the fatty acid solution supplied to the unit mass of the liquid 22 is adjusted. The method of adding quality is preferred. The flow rate of the fatty acid solution 27 with respect to the flow rate of the dope 22 is controlled, and the added concentration of the fatty acid 25 is adjusted.

By adding the fatty acid 25 to the dope 22, precipitation is also suppressed.

<fatty acid>

The fatty acid 25 used in the present invention is a fatty acid having a carbon number of 12 or more and 22 or less. Among them, linear fatty acids are preferred, saturated fatty acids are preferred, and fatty acids cited in Table 1 are particularly preferred.

<Cellulose Telluride>

It is particularly preferable that all the conditions of the following formulas (1) to (3) satisfy the ratio of the degree of substitution of the thiol group in the cellulose halide 20, that is, the degree of substitution of the thiol group (hereinafter referred to as the thiol substitution degree). Further, in (1) to (3), both A and B are thiol substitution degrees, the fluorenyl group in A is an acetamyl group, and the fluorenyl group in B is a group having 3 to 22 carbon atoms.

The glucose unit constituting cellulose and having β-1,4 linkage has a free hydroxyl group at the 2, 3 and 6 positions. The cellulose halide 20 is a polymer in which a part or all of the cellulose hydroxyl group is esterified and a hydrogen of a hydroxyl group is substituted into a mercapto group having a carbon number of 2 or more. In addition, if one of the hydroxyl groups in the glucose unit is 100% esterified, the degree of substitution is 1, so when it is a cellulose halide, if the hydroxyl groups at the 2, 3, and 6 positions are each 100% esterified, The degree of substitution becomes 3.

Here, in the glucose unit, the degree of substitution of the thiol group at the 2-position is set to DS2, the degree of substitution of the thiol group at the 3-position is set to DS3, the degree of substitution of the thiol group at the 6-position is set to DS6, and "DS2+DS3+DS6" The degree of substitution of all thiol groups is preferably 2.00 to 3.00, more preferably 2.22 to 2.90, and further preferably 2.40 to 2.88. Further, "DS6/(DS2+DS3+DS6)" is preferably 0.32 or more, more preferably 0.322 or more, and further preferably 0.324 to 0.340.

The thiol group may be used alone or in combination of two or more. When the fluorenyl group is two or more kinds, one of them is preferably an acetamino group. The sum of the substitution ratios of the thiol groups of the hydrogens of the hydroxyl groups of the 2, 3, and 6 positions is set to DSA, and the sum of the substitution degrees of the sulfhydryl groups other than the ethyl group in the 2, 3, and 6 positions is set to For DSB, the "DSA+DSB" value is preferably 2.2 to 2.86, and 2.40 to 2.80 is particularly preferred. A DSB of 1.50 or more is preferred, and a 1.7 or more is particularly preferred. Further, it is preferable that 28% or more of DSB is a hydroxyl group at the 6-position, and more preferably 30% or more, more preferably 31% or more, and particularly preferably 32% or more. Further, the "DSA+DSB" value of the 6-position of the cellulose halide 20 is preferably 0.75 or more, more preferably 0.80 or more, and particularly preferably 0.85 or more. By using the cellulose halide as described above, it is possible to obtain a preferable solubility in order to prepare a polymer solution used for forming a solution.

The fluorenyl group having 2 or more carbon atoms may be an aliphatic group or an aryl group, and is not particularly limited. For example, there may be an alkylcarbonyl ester of cellulose, an olefinic carbonyl ester or an aromatic carbonyl ester, an aromatic alkylcarbonyl ester or the like, which may each have a further substituted group. Examples thereof include a fluorenyl group, a butyl fluorenyl group, a pentamidine group, a hexyl fluorenyl group, a decyl group, a decyl group, a dodecyl fluorenyl group, a tridecyl fluorenyl group, a tetradecane fluorenyl group, a hexadecane group, an octadecane group. Anthracenyl, isobutyl fluorenyl, tert-butyl fluorenyl, cyclohexanecarbonyl, anthracenyl, benzamyl, naphthalenecarbonyl, cinnamyl, and the like. Among them, a propyl fluorenyl group, a butyl decyl group, a dodecyl fluorenyl group, an octadecyl fluorenyl group, a tert-butyl fluorenyl group, an oil fluorenyl group, a benzamidine group, a naphthylcarbonyl group, a cinnamyl group, etc. are more preferable, and a propyl sulfhydryl group good.

<1st solvent>

As the first solvent 21, it is possible to produce a cellulose halide by using a solution film. A well-known solvent as a solvent of a dope at the time of a film. For example, it is dichloromethane, various alcohols, various ketones, etc. Further, the first solvent 21 may be a mixture of a plurality of solvent components. In this case, a mixture in which a poor solvent is added to a good solvent of cellulose halide may also be used.

<2nd solvent>

When the second solvent 26 contains a good solvent for the fatty acid 25, it may be a single component or a mixture of a plurality of components. The second solvent 26 preferably contains a compound which is used in combination with the component used as the component of the first solvent 21 from the viewpoint of more reliable and more rapid homogenization after being added and mixed in the dope 22 .

Hereinafter, examples of the invention and comparative examples of the invention will be given. The details are described in the examples, and only the conditions different from the examples are described in the comparative examples.

[Examples]

The dope 22 of the following formulation was produced by the first dissolution apparatus 15. The first solvent 21 is a mixture of three components, the first component is dichloromethane, the second component is methanol, and the third component is n-butanol.

The fatty acid solution 27 is produced by supplying the fatty acid 25 and the second solvent 26 to the second dissolution device 16. The mass ratio (M2/M1) of the fatty acid 25 used in the type of the fatty acid 25 used and the solid content of the dope 22 was changed as Example 1 to Example 9. The kind of the fatty acid 25 and M2/M1 in the respective examples are shown in Table 2. Further, the second solvent 26 is set to have the same composition as that of the first solvent 21 .

The fatty acid solution 27 is added to the dope 22 flowing from the first dissolution device 15 toward the casting die 18 in the first pipe L1 to prepare a casting dope 30. Further, a mixing device 17 is provided downstream of the addition position PA of the first pipe L1, and the dope liquid 30 is mixed and homogenized.

The dope 30 is continuously cast for 3 hours on the drum 41 of the film manufacturing unit 12. The drum 41 has a circumferential surface width of 10 cm and a diameter of 5 cm. Regarding the stain attached to the drum 41 Scale, the following evaluation was performed.

In each of the examples, the cleaning property, the suppression of precipitation, and the transparency of the film 40 were evaluated by the following methods and standards. The evaluation results of the respective examples are shown in Table 2.

Cleaning

In a state where the drum 41 was rotated at a speed of 1 m/min in a single direction, the dirt adhering to the circumferential surface of the drum 41 was wiped with a cloth containing a solvent. The solvent contained in the cloth was a mixture of acetone/dichloromethane mixed in a mass ratio of 1/1. The washing performance was evaluated by the following criteria on the basis of the number of revolutions of the drum 41 required for the dirt on the drum 41 to disappear.

A: The dirt on the drum 41 disappeared in the range of one rotation or more and three or less rotations.

B: The dirt on the drum 41 disappeared in the range of 4 or more rotations or less.

C: The dirt on the drum 41 disappeared in the range of 6 or more rotations and 10 or less rotations.

D: Even if it is rotated 11 times or more, dirt remains on the drum 41.

In addition, A and B are the levels of cleanability, and C and D are the levels of failure.

2. Precipitation inhibition

When precipitation occurs, the circumferential surface of the drum 41 loses luster corresponding to the amount of dirt, and the circumferential surface of the drum 41 is whitened. Therefore, the glossiness of the circumferential surface of the drum 41 is obtained, and the suppression effect of precipitation is evaluated based on the glossiness. The evaluation method is specifically as follows.

Before the film 40 is produced, the drum 41 is previously disposed in the dark room. In the dark room, white light is irradiated to the circumferential surface of the drum 41 at a predetermined angle from a predetermined direction. A light receiving device is disposed at a position different from the light source of the white light, and the light receiving device measures the amount of light of the reflected light of the white light reflected by the drum. The amount of light measured was set to Q1.

The continuous manufacture of the film 40 was started and the production was temporarily stopped at the time of 40 hours.

The drum 41 is removed from the casting device, and the drum 41 is again disposed in the dark room. Further, the amount of reflected light was measured under the same conditions as in (1). The amount of light measured was set to Q2.

The value obtained by (Q2/Q1) × 100 was taken as the gloss (unit: %).

A: The gloss is 80% or more and 100% or less.

B: The gloss is 65% or more and less than 80%.

C: The gloss is 50% or more and less than 65%.

D: The gloss is 0% or more and less than 50%.

Further, A and B are levels at which the suppression effect of precipitation is acceptable, and C and D are levels of failure.

3. Film transparency

When the amount of the fatty acid 25 added to the dope 22 is too large, the fatty acid 25 precipitates on the surface of the film 40 with time, and the film 40 is whitened. The degree of whitening can be measured by haze, and the degree of whitening becomes larger as the degree of whitening becomes larger and the transparency of the film is deteriorated. Further, the possibility of precipitation of the fatty acid 25 is increased by being placed in a heated state. Therefore, the transparency of the film 40 was evaluated by the following method.

The obtained film 40 was cut into 40 mm × 80 mm, and the haze at 25 ° C and 60% RH was measured. The haze was measured by a haze meter (HGM-2DP, a Suga test machine) and measured in accordance with JIS-6714. The measured value was set to H1.

The film 40 subjected to the measurement of (1) was allowed to stand in an environment of 150 ° C for 2 hours.

After the heat treatment of (2), the haze of the film 40 was measured by the same haze meter as (1). The measured value was set to H2.

The haze was determined based on the change in the heat treatment as the value of H2/H1.

A: The value of H2/H1 is less than 1.2.

B: The value of H2/H1 is 1.2 or more and less than 1.5.

C: The value of H2/H1 is 1.5 or more.

Further, A and B are levels at which the transparency of the film 40 is acceptable, and C is a level of failure.

[Comparative example]

In Comparative Example 1, the fatty acid 25 was not added to the dope 22, but the dope 22 was directly supplied to the casting. In Comparative Examples 2 to 7, the fatty acid 25 and the second solvent 26 were supplied to the second dissolution apparatus 16 to prepare a fatty acid solution. The mass ratio (M2/M1) of the fatty acid 25 to the type of the fatty acid 25 to be used and the solid content of the dope 22 was changed. The kind of the fatty acid 25 and M2/M1 in each comparative example are shown in Table 2. Other conditions are the same as in the embodiment.

The same evaluation as in the examples was carried out for each comparative example. The evaluation results are shown in Table 2.

10‧‧‧solution film making equipment

11‧‧‧Concentrate manufacturing unit

12‧‧‧ Film manufacturing unit

15‧‧‧1st dissolution device

16‧‧‧Second dissolving device

17‧‧‧Mixed device

18‧‧‧casting mode

19‧‧‧ plasticizer

20‧‧‧ Cellulose Telluride

21‧‧‧1st solvent

22‧‧‧Liquor

25‧‧‧ fatty acids

26‧‧‧2nd solvent

27‧‧‧ fatty acid solution

30‧‧‧Running dope

31‧‧‧Valves

34‧‧‧casting device

35‧‧‧ tenter

36‧‧‧Roll drying device

37‧‧‧Winding device

40‧‧‧ film

41‧‧‧Roller

42‧‧‧cast film

45‧‧‧ peeling roller

46‧‧‧ needle board

47‧‧‧ catheter

50‧‧‧roll

L1‧‧‧1st piping

L2‧‧‧2nd piping

PA‧‧‧Add location

PC‧‧‧ casting position

PP‧‧‧ peeling position

Claims (17)

A method for producing a cellulose oxime film, wherein the method comprises the steps of: (A) adding a fatty acid having a carbon number of 12 or more and 22 or less to the cellulose oxime solution, wherein the cellulose oxime solution is a ratio in which the ratio of the mass of the fatty acid to the sum of the mass of the cellulose halide and the plasticizer is 1 × 10 ^-4 or more and 3 × 10 ^-3 or less, in which the cellulose halide and the plasticizer are dissolved in the liquid of the solvent. a predetermined amount of the aforementioned fatty acid is added to the aforementioned cellulose halide solution; (B) casting the aforementioned cellulose halide solution to which the aforementioned fatty acid is added to the surface of the support to form a cast film, wherein the support is The casting position and the peeling position are circulated, wherein the casting position is a position at which the cellulose telluride solution is cast, and the peeling position is a position at which the casting film formed by casting is peeled off; (C) from the support body The surface is peeled off from the cast film; and (D) the stripped film is dried. The method for producing a cellulose oxime film according to the above aspect of the invention, wherein the fatty acid is a linear fatty acid. The method for producing a cellulose oxime film according to the above aspect of the invention, wherein the fatty acid is a saturated fatty acid. The method for producing a cellulose oxime film according to the second aspect of the invention, wherein the fatty acid is a saturated fatty acid. The method for producing a cellulose oxime film according to claim 1, wherein the fatty acid is dissolved in a solvent to prepare a fatty acid solution, and in the step A, the fatty acid solution is added to the cellulose oxime solution. The method for producing a cellulose oxime film according to claim 2, wherein the fatty acid is dissolved in a solvent to prepare a fatty acid solution, and in the step A, the fatty acid solution is added to the cellulose mash solution. The method for producing a cellulose oxime film according to claim 3, wherein the fatty acid is dissolved in a solvent to prepare a fatty acid solution, and in the step A, the fatty acid solution is added to the cellulose mash solution. The method for producing a cellulose oxime film according to the fourth aspect of the invention, wherein The fatty acid solution is prepared by dissolving the above-mentioned fatty acid in a solvent, and the aforementioned fatty acid solution is added to the cellulose halide solution in the above-mentioned step A. The method for producing a cellulose oxime film according to the first aspect of the invention, wherein the cellulose mash solution is continuously supplied to the casting device performing the step B, and the cellulose flowing toward the casting device The hydrazine solution is continuously added to the aforementioned fatty acid solution. The method for producing a cellulose oxime film according to the second aspect of the invention, wherein the cellulose mash solution is continuously supplied to the casting device performing the step B, and the cellulose flowing toward the casting device The hydrazine solution is continuously added to the aforementioned fatty acid solution. The method for producing a cellulose oxime film according to the third aspect of the invention, wherein the cellulose mash solution is continuously supplied to the casting device performing the step B, and the cellulose flowing toward the casting device The hydrazine solution is continuously added to the aforementioned fatty acid solution. The method for producing a cellulose oxime film according to the fourth aspect of the invention, wherein the cellulose mash solution is continuously supplied to the casting device performing the step B, and the cellulose flowing toward the casting device The hydrazine solution is continuously added to the aforementioned fatty acid solution. The method for producing a cellulose oxime film according to the fifth aspect of the invention, wherein the cellulose mash solution is continuously supplied to the casting device performing the step B, and the cellulose flowing toward the casting device The hydrazine solution is continuously added to the aforementioned fatty acid solution. The method for producing a cellulose oxime film according to the sixth aspect of the invention, wherein the cellulose mash solution is continuously supplied to the casting device performing the step B, and the cellulose flowing toward the casting device The hydrazine solution is continuously added to the aforementioned fatty acid solution. The method for producing a cellulose oxime film according to the seventh aspect of the invention, wherein the cellulose mash solution is continuously supplied to the casting device performing the step B, and the cellulose flowing toward the casting device The hydrazine solution is continuously added to the aforementioned fatty acid solution. The method for producing a cellulose oxime film according to the eighth aspect of the invention, wherein the cellulose mash solution is continuously supplied to the casting device performing the step B, and the cellulose flowing toward the casting device The hydrazine solution is continuously added to the aforementioned fatty acid solution. An apparatus for producing a cellulose oxime film, wherein the apparatus comprises: an additive portion for adding a fatty acid having a carbon number of 12 or more and 22 or less to a cellulose oxime solution, wherein the cellulose oxime solution is a fiber The ratio of the mass of the fatty acid to the sum of the mass of the cellulose halide and the plasticizer is in the range of 1 × 10 ^-4 or more and 3 × 10 ^-3 or less, in which the primed compound and the plasticizer are dissolved in the liquid of the solvent. a predetermined amount of the aforementioned fatty acid is added to the cellulose mash solution; a casting device forms a cast film from the cellulose mash solution to which the fatty acid is added; and a casting die to add the cellulose to which the fatty acid is added The telluride solution flows out, wherein the casting die is disposed in the casting device; the support body circulates at a casting position and a peeling position, wherein the support body is disposed in the casting device, and the casting position is cellulose crucible a position where the compound solution is cast, the peeling position is a position at which the casting film formed by casting is peeled off; and a peeling portion is peeled from the support body The cast film; and a drying means, for the release of the cast film is dried.